An anterior cruciate ligament (ACL) that has ruptured and is non-repairable is generally replaced arthroscopically by a tissue graft. The tissue graft can be harvested from a portion of a patellar tendon having so called “bone blocks” at each end, and from the semitendonosis and gracilis. Alternatively, the tissue graft can be formed from synthetic materials or from a combination of synthetic and natural materials.
The replacement tissue graft is implanted by securing one end of the tissue graft in a socket formed in a passage within the femur, and passing the other end of the graft through a passage formed in the tibia. Generally, sutures are used to affix each end of the tissue graft to a fastener (e.g., an interference screw or a post), which is then secured to the bone.
It is also known to use a graft fixation member, e.g., a fixation button, to secure the tissue graft at the femoral cortex, as described in U.S. Pat. No. 5,306,301 (“the '301 patent”) hereby incorporated by reference in its entirety. When using a fixation button, the femoral passage generally includes a relatively larger diameter portion for receiving the graft, and a smaller diameter, passing channel near the femoral cortex for receiving a length of suture that runs from the tissue graft to the fixation button. By measuring the total length of the femoral passage and the length of the larger diameter portion of the femoral passage, the surgeon determines the appropriate length of suture material for attaching the fixation button to the tissue graft.